The product $(a+b)(c+d)$
Practice
Expand and simplify.
*Write your answers with powers of $x$ in descending order. $\left(\square x^2 \pm \square x \pm \square\right)$
$\left(x+8\right)\left(x+9\right)$
$\left(x+1\right)\left(x+6\right)$
$\left(x-1\right)\left(5+x\right)$
$\left(-x+9\right)\left(-9+x\right)$
$\left(-1+x\right)\left(-x+9\right)$
$\left(8+x\right)\left(x-5\right)$
$\left(-4+x\right)\left(1+x\right)$
$\left(4-x\right)\left(-4+x\right)$
$\left(2x-3\right)\left(-4x+3\right)$
$\left(-5x+6\right)\left(2x-1\right)$
$\left(-3x+4\right)\left(7+6x\right)$
$\left(-9x+1\right)\left(-7+3x\right)$
$\left(-2+7x\right)\left(-3x+2\right)$
$\left(3+2x\right)\left(2x-5\right)$
$\left(-3+5x\right)\left(6+5x\right)$
$\left(1-5x\right)\left(-5+x\right)$